I'm looking to play the first few Final Fantasy games over the portable GBA format, and I bought a first version GBA SP but I am wondering if I should trade up to the GBA SP version 2 (with the backlit and brighter screen) or even trade up to one of the DS models? I mean, the screen is bright enough to see to play the game, but if I'm going to be playing it for 40 hours (I'm told) maybe a brighter screen would be better? But I cannot find an actual spec sheet for any of these units that describes the difference in brightness, so that I can estimate whether it is practically worth more to upgrade to a later model?